The average smartphone has a consumer lifetime of just three years, but the lithium ion batteries inside are often discarded with them even though they can last up to five years, creating extra e-waste and squandering batteries that are still useful.
To cut down on this waste, researchers at Kyung Hee University in Seoul have developed a model to recycle unspent lithium ion batteries into energy storage for solar-powered LED lighting in rural homes, which commonly use inefficient candles and kerosene lamps or improvise old lead-acid car batteries that tend to have a short lifespan. The research team describes the logistics of the recycling and repurposing effort in the Journal of Renewable and Sustainable Energy.
A standard smartphone battery can power a 1W LED lamp for about three hours or a 0.5W lamp (bright enough for reading and writing) for about six hours, notes Boucar Diouf, a professor in the Department of Information Display at Kyung Hee University. Adding a small solar panel to the maintenance-free system will give it a lifetime of roughly three years. The researchers also constructed a full 12V system made of three phone batteries, a 5W LED lamp and a small solar panel for less than $25 that can light up a room for about five hours per day.
The team’s next step involves setting up battery collection and e-waste recycling systems, as well as working to reduce the cost of solar systems for rural populations in developing countries. Pilot projects in Senegal and sub-Saharan Africa are planned within the next year.